v2.2.1 - formatter fix (#23)

Fixed

• %v discarded the cause chain. Error() and %s returned the full message, while %v
  printed only the outermost frame — so a wrapped cause was recorded everywhere except where anyone
  looks for it. %v is the verb fmt.Println(err) uses and the one most loggers call.

v2.2.0: Match the standard library's As signature

Changed

• As now matches the standard library's signature, As(err error, target interface{}) bool,
  replacing As(err, test error) error.

Fixed

Eight defects, all found by a new contract test suite (contract_test.go) organised by obligation
rather than by function. Coverage 95.9%, race-clean.

• Panics on nil. doc.go promises every method works with nil values; four did not.
  (*E).Error, (*E).Is and (*E).MarshalJSON dereferenced a nil receiver, and (*E).Is also
  panicked whenever the frame carried no annotation of its own — reflect.TypeOf(nil) returns a
  NIL reflect.Type, and calling Comparable on that panics rather than answering false. The
  package-level Is had the same flaw. Both now share a comparableErrors helper.
• **New and Wrap corrupted any message contain

v2.1.4: Traverse multi-errors in Is and As

Fixed

• Is and As now traverse multi-errors. An error may wrap several causes — errors.Join, or
  fmt.Errorf with more than one %w — and those implement Unwrap() []error, which the
  single-error Unwrap cannot express.
• Unwrap still returns nil for a multi-error, as std/errors.Unwrap does — there is no single
  previous error to return. This is now documented rather than implicit; callers walking a chain
  themselves must branch on Unwrap() []error.

v2.1.3: Make wrapped errors visible to the standard errors package

Added

• Interoperation tests against the standard library's errors package (interop_test.go).

Changed

• func (e *E) Unwrap() error now returns the wrapped error itself. It previously re-boxed a
  wrapped error that did not implement std/errors.Error as &E{err: prev}. That box carried no
  prev, so the chain ended there and the original error value was never handed to the caller — its
  own Unwrap, Is and As were never consulted. The consequence was that errors.As could only
  ever match *E, since no other concrete type was ever yielded, so anything built on errors.As
  could not see through a wrap. gRPC is the sharpest example: status.FromError is errors.As for an
  interface{ GRPCStatus() *Status }, so a wrapped status error was reported as codes.Unknown — an
  HTTP 500 — including for failures that were plainly the caller's fault, such as an unacceptable auth
  token.
• func Is(err, test error) bool no longer ends the walk early. It returned the first link's Is
  answer directly; every *E has an Is method, so a false there ended the search and a sentinel
  further down was unreachable. A negative answer from one link now continues to the next.
  func (e *E) Is(error) bool is unchanged and still searches the chain — the standard library calls
  that hook as ok && x.Is(target), so its answer never terminated errors.Is's own walk.
• func (e *E) Error() string includes the wrapped message, "outer: inner", as
  fmt.Errorf("%w") produces. Returning only the frame's own message discarded everything beneath it
  wherever an error is rendered through Error() rather than a %+v verb — which is most of the
  places that reach a user, including an HTTP or gRPC response body. The trace and JSON formats print
  one line per frame and now use each frame's own message, so their output is unchanged.

v2.1.1

Changed

• Updated various docs

v2.1.0

Added

• Additional documentation
• Pre-generics implementation of As, returns the error instance when found

Changed

• Upgrade to bdlm/std v2.1.0
• Cleaner type checking in Is methods

Removed

• deprecated Has methods, use Is instead

v2.0.1

v2.0.0 - 2020-05-02

Changed

• Refactoring to better implement the std/errors.Error interface

v2.0.0

v2.0.0 - 2020-05-02

v2.0.0 is the production release of the v0.2.0 development branch.

Added

• go.mod
• github.com/bdlm/std/v2/errors interfaces

Changed

• licence changed from BSD to MIT
• replace interfaces with github.com/bdlm/std/v2/errors implementations
• simplified formatting and marshalling logic
• renamed GetCaller(error) std_err.Caller to Caller(error) std_err.Caller

Removed

• unused code

v0.2.1

Added

• Documentation and examples

Changed

• Minor formatting updates and cleanup

v0.2.0

This release is a full rewrite of the errors package. See the README for further details.

Added

• Caller interface
• Error interface
• Exported methods
  • Errorf(msg string, data ...interface{}) Error
  • GetCaller(err error) Caller
  • Has(err, test error) bool
  • Is(err, test error) bool
  • Trace(e error) Error
  • Track(e error) Error

Changed

• Exported methods
  • New(code std.Code, msg string, data ...interface{}) *Err
    • New(msg string) Error
  • Wrap(err error, code std.Code, msg string, data ...interface{}) *Err
    • Wrap(e error, msg string, data ...interface{}) Error

Removed

• Exported methods
  • From(code std.Code, err error) *Err
• Support for error codes
• Support for sanitized vs raw error messages
• Support for HTTP status codes